Why did Japan attack us 70 years ago today, other than the usually cited existential reasons and the fact that they thought they could and get away with it?

We sometimes forget that their expansionism in Manchuria quickly put them in collision with the Soviet Union, and for much of the summer of 1939 they waged a vicious and costly border war against the Soviets — one that they eventually lost and which led to their signing a non-aggression pact with Russia by spring 1941.

The Japanese had bitterly complained that, in the midst of their ordeal, their supposedly anti-Communist ally Nazi Germany had without warning agreed to a duplicitous non-aggression pact with the Soviet Union. Indeed, the Ribbentrop-Molotov deal was signed on August 23, 1939, amid some of the worst fighting for the Japanese on the Russian eastern front. If Hitler thought that he had a green light to go into Poland, Stalin was equally relieved that he too had only a one-front war and no worries about the Japanese as he gobbled up his share of Poland.

The irony was, of course, that when Hitler invaded Russia the next year in June 1941, Stalin was freed up by Japanese neutrality to send critical divisions from the east; in tit-for-tat fashion, the Japanese had done to Germany what Germany had just earlier done to it. After the stall at Moscow, it is strange to read of growing Germany exasperation with the Japanese, given prior Nazi unconcern with Japan’s war with Russia.

As for the Japanese in spring 1941, with their own rear largely freed from worries over the Soviets and the army somewhat in disrepute after the costly and losing conventional border war and the humiliation of being loud proponents of the now dubious alliance with Hitler, the navy was able to make the argument that a one-front, primarily carrier war against the Americans made some sense, and a simultaneous one against the naturally rich colonies of the weaker European Pacific powers even more sense given their losses in Europe to Hitler.

Indeed, until August 1945, it was the United States, not Japan, that had a traditional two-front war. We rarely talk of Stalin’s duplicity in this regard: While we were suffering terrible casualties from the Japanese, supplying Russia, conducting bloody campaigns in North Africa, Sicily, Italy, and over the skies of Europe, and being hectored by the Soviets to open a second front in Europe, the Soviets honored their non-aggression pact with Japan, freeing up hundreds of thousands of veteran troops to be used against us on the islands. I never understood why history books focus on Stalin’s exasperation with our supposedly tardy invasion of Normandy, when he was completely unwilling to open a second front against Japan — until it was utterly wrecked in August 1945 and there were easy pickings to be had in the region.

It is often said that Admiral Yamamoto, the architect of Pearl Harbor, was a sort of liberal (at least in the militaristic Japan of the times) and a visionary who opposed the Tripartite Pact, who did not support the Manchuria occupation, and who had deep reservations about attacking the U.S. The famous quotes about awakening a “sleeping giant” and running wild for (only) six months are often, and dubiously, attributed to him. He is also held to have been a brilliant strategist in his emphases on carriers instead of battleships.

Perhaps. But it may be just as likely that Yamamoto’s earlier years in the United States, at Harvard in particular, rather than convincing him of the futility of attacking such an industrial colossus had encouraged his prejudices that Western society, especially in its Roaring Twenties excesses, was decadent and lacked the martial steel for an eventual war with the Japanese. Yamamoto’s failure to plan for a follow-up after Pearl Harbor, whose fuel depots and shipyards could have been neutralized for several months, and the idiotic plan to divide his Midway forces by sending valuable assets up to Alaska, don’t support the image of either a brilliant thinker or a classical liberal surrounded by closed military minds.

One final thought. The growth of Japan in the 1920s and 1930s and the alarm that it caused in the Pacific, its increasingly illiberality and nationalism, the enormous industrial and military progress that it had made in emulating European economies and Western armed forces, the concurrent impressions that a Depression-era America was a sinking rather than a rising power, and a general sense that the Japanese model was superior to the alternatives offer some general parallels to the current comparative status of China and America in the Pacific. Let us hope that we learn the lessons of Pearl Harbor, namely that anything is possible at any time, that deterrence ultimately keeps the peace, and that deterrence is a combination of known superior military strength and a certainty among concerned parties that such overwhelming power will be used in defense, and thereby will assure the aggressor that its attack will prove suicidal.